Gear-rolling machine.



H. N. ANDERSON.

GEAR ROLLING MACHINE.

APPLICAUON mw JULY 26. 19|5.

Pltnwd Sept. 25, 1917.

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H. N. ANDERSON.

GEAR ROLLING MACHINE.

APPucmoN man JuLY 2s. 1915.

Patented Sept. 25, 1917.

9 SHEETS-SHEET 2.

H` N. ANDERSUN.

GEAR oLLmG MAcHlNE.

APPLICATION rILiD )ULY 26.1915. 1,240,91 6. y Patented sept.. 25,1917.

9 SHEETS-SHEE 3.

H. NA ANDERSON.

GEAR ROLLING MACHINE.

APPLlcMson man um 26.1915.

Patenteiisopt. 25, 15H7.

9 SHEETS SHEET 4.

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H. N. ANDERSON.

GEAR ROLLING MACHINE.

APPucnTsoN mm Jun 26.1915.

Patented Sept. 25, 1917.

9 SHEETS-SHEET 6.

H. N. ANDERSON.

GEAR ROLLING MACHINE.

Awucmlou min mur 26,1915.

Patented Sept. 25, 1917.

9 SHEETS-SHEET B.

wil/naman I v H. N. ANDERSON. GEAR nomma MACHINE.

APPLICATiON FlED JULY 26# ISIS. 1,240,91 6. Patented Sept 25, 1917.

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UNITED STATES PATENT OFFICE.

HAROLD N. ANDERSON, OF CLEVELAND, OHIO, ASSIGNOR TO THE ANDERSON ROLLED GEAR COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

GEAR-ROLLING MACHINE.

Application filed July 26, 1915.

To all oleo/o 'it muy Concern:

lw it known that l, llvnoLn N. ANDEL sox. a citizen of the United States, residing at (`|c\e|and, county of Cuyahoga, State of Ohio. have invented certain new and uscful improvements in Gear-Rolling*r Machines, ol' which the followingr is a full, clear, and exact description.

This invention is related to my application Serial No. 800,251 and to two divisions which have been' carved therefrom, Serial Nos. 55,976 and 55,977. Each ot' these shows machines `for rolling bevel gears, having certain common characteristics; for exainple shrouds which confine the die-roll teeth. lt is also related to my application Serial No. (313,010, in that the die-roil has certain elmracteristics found in a rectitineal rack; itis in fact what is often referred to as a circular rack, though more commonly known as a crown gar. Serial No. 800.251.

as now constituted, discloses both a conical4 and a crown die-roll arranged to approach the blank longitudinally; it also contains generic claims for a gear rolling machine embodying a longitudinally movable dic roll. In the present application l claim broadly a gear rolling machine having a longitudinally movable crown dieroll.

'lhe valuable qualities of rolled gears have been pointed ont in one or more of the above mentioned applications, so it, is unnecessary to do so here.

One of the principal objects of the present invention is to insure uniform treatment of the blanks by providing automatic mechanism for clann'iing' the blank in the holder,

pressingr the rotating die-roll into the blank k at a definite velocity, suspending the pressure and allowing the die-roll and blank to rotate tog-ether for a dctinite period of time, withdrawing the die-roll., releasing the blank and stopping its rotation. The meehanism is timed so as to complete the cycle of operation while the blank completes a given number of revolutions.. This automatic control is an improvement over the Astructure disclosed in said appleation Se rial No. 851.275. among` other respects, in that thc die Ina'v be pressed into thc blank at any predetermiucd velocity relative tothe velocit)| ot' rotation of ythe die and blank, while the former structure does not possess this universality of adaptation. lin both devices, however, the teeth are sunk into the Specification of Letters Patent.

Patented Sept. 25, 1917.

Serial No. 41,857.

blank while it turns a `given number of revolutions and this is the subject of broad claims in said application Serial No. 851,275.

Another principal object is to give the die-roti a certain universality of adaptation. liv moving' the die-roll longitudinally to pressA it into the blank it is enabled to roll teeth having' various clniracteristies. Being a. crown rear the die-roll is capable of rolliupr anyY bevel gear otl its pitch and radius, from one having the largest number of teeth possible in a bevel gear not a crown gear to a pinion havin,Ir the fewest possible teeth. This universalityv is made available by a swiveled mounting' for the blank which permits ot :in v angle between the die-roll and blank axes.

Another principal object is to avoid moving the timing.;- gears in bringing the dieroll into action. The timing gears, one of which is a crown gear, are properly cn lneshed to a desired depth` and remain so all the while the die-roll operates on the blank. The, angle formed b v the axis of the die-roll with that of the blank remains fixed while the teeth are formed.

Anotherv principal object is to fill out the teeth at their extremities. This is done by confining the tooth receiving' part ot the blank between shrouds. Means are pro` vided for doing this without impedingr insex-tion and removal of the blanks.

Other objects are to provide extractingde vices for the blanks when completed. and to improve f.;t1ie1^all \Y upon machines for rolling: gears.

ln thc accompanying' drawings:

Figure 1 is a plan of the machine in 0peration.

Fig. Q is a front elevation of the machine when in operation.

Fig. 3 is an elevation of the left end.

Fig. 4 is a sectional elevation on line 4, Fig. 1.

Fig. 5 is an enlarged view ot' the die-roll end ofthe machine.

Fig. t' is an enlarged plan view of the blank carriage shown at the right in Fig. 1, showing the operation of the blank e.'- tractor.

Fhr. T is a view of a modified form of carriage.

Fig. 7^ is a detail showing parts of Fig. 7 in a ditferent position.

Fig. 8 is a sectional plan of the timing gears, blank holder, die-roll, ete.

Fig. 9 is a similar view of a modified structure.

Figs. 10, 11 and 12 are sectional plan views of three different blank clamping and shrouding devices.

Fig. 13 is a sectional plan of the timing gears and blank holder, with a` shrouded die-roll.

Fig. 14 is a diagrammatic plan of the controlling cam for the die roll;

Fig. 15 is a similar view of the controlling cam for the blank holder, and

Fig. 1G is a diagrammatic view of one of the pressur-e cams.

Fig. 17 is a plan of a modified structure in which the power is applied at the blank end of the machine and the die-roll is swung on a pivot instead of moved longlmclinally.

Fig. 18 is a diagrammatic illustration of the long and short addendum.:a

Fig. 19 shows a. modified flor-m of' gear rolling machine in which the die-roll is manuallgiifadvanccd longitudinally.

Figgtllgshows the same device with the die in Contact with the blank.

Similar numerals refer to like parts in all of the views.

Referring to the drawings, 25 indicatesthe base, which carries a motor 26 whose pinion 27 meshes with a gear 28 carried by a shaft 29 mounted in bearings also carried by base 25. Gear 28 is loosely mounted upon shaft 29 and is connected thereto when desired by a clutch 30. This clutch is thrown in by means of a shifting lever 31 in the usual way. A worm 32 carried by shaft 29 meshes with a Worm wheel 33 and drives the timing wheel 34. Fig. 5 shows the normal position of this wheel when at rest. The motor is normally running and when the operator wishes to start the machine he throws in the cluffh with the lever 31 which starts the shafti to rotatingr and driving the timing wheel in the direction shown in Fig. 5. :The motor continues to run until the lug 35 on the timing wheel engages the roller 36 on the end of an arm 37 extending from the shifting lever 31 and throws out the clutch. The timing wheel therefore rotates once and then stops the motor. The parts have suiiicient momentum to carry the lug 35 past the roller, so as not to interfere with the succeeding operation of the shifting lever.

A gear 40 is rigidly secured to shaft 29 and meshes with a gear 41 rigidly secured to `a hollow shaft 42 (see Figs. 4 and 5) which rotates in a bearing 43, said bearing having a-suitable bushing 44. The other end of Vshaft 42 is enlarged and forms a shoulder and has an outwardly extending flange 48 to which is bolted the crown gear 49. A band brake 50 surrounds the head 47 and is operated by a lever 51.

A hollow shaft GU is,arranged to slide longitudinally in shaft 42 but is made to revolve in unison therewith by splines 61 see Fig. 4). One end of this shaft has a flange 62 which resides in the hollow part of head 47 (see Fig. 8). A plate G3 is bolted to the flange and a crown gear (il is bolted to the plate. This gear is the die-roll. Obviously diifcrent die-rolls may be bolted to the plate, and it' desired the plate may he changed. Making the die-roll and plate separately simplifies the work of making the die-roll. The shaft G0 extends to and is journaled in a bearing 65, being adapted to rotate and slide longitudinally"therein.V An arm 66 is loosely mounted on the shaft1 the hub G7 thereof lying against bearing (3.5. The oppo site end of the hub has two projections 68, one of which is visible' in the'drawings. These projections lie between complementary projections on a. collar 69. also loosely mounted on shaft G0, this collar being al lowe-l to slide parallel to the axis of the shaft but prevented from rotatingr by a slotted arm 7U, which lies on a pad formed on the base 25 and is retained in position by bolts 7l. The collar bears against a ball thrust bearing 72, one element whereof is threaded and screwed on the shaft and held in position by a jam nut 73. The sides of the projections 68 are oblique and the projections on collar (i9 have complementary Obliquity", so that when the arm 66 is rocked upward these` oblique sides act as cams and move the shaft (l0 longitudinally. ln view of this function the hub 6T will hereinafter be referred to as a` pressure cani. A compression spring 74 opposes this cam and tends to move the shaft in the opposite diA rection.

A plunger S0 is arranged to more longituY dinally in shaft GO and is also free to rotate therein. The plunger is moved longitudinally by an arm Si, pressure cam 82. non rotatable follar 83, and thrust bearing 84 in the same manner as is shaft (30, and is moved in the opposite direction by the compression spring 85. The plunger is also movable manually by means of a lever 86 which operates in a l.c rooved collar 87 interposed between the collar 83 and thrust bearing 84. The left hand end of the plunger is supported in a bearing 88.

The blank carriage comprises af'plate 90, bearings 91 and shaft The plate 90 lies on base 25 and is arranged to swing on a pivot 93 the axis of which passes through the axis of the gear 49 and coincides with the y pitch-plane of said gear. The axis of shaft 92 lies in the same plane as the axis of the gear 49. T slots are provided in the base to receive the heads of bolts 04 whereby plate 90 may be secured in any desired position about the pivot 93. Set screws 95 are screwed into the end of the plate in such position that their heads bear against a flange 9G on .the base and relieve the pivot 93 of strain. A graduated scale 97 is formed on the flange 96 and the plate carries an index 98, by which to set the carriage at any dcsired angle with referenceto the die-roll axis. The end o'f shaft 92 carries a flange 00, which bears against the end of bearing 01, and4 a bevel gear 100 is bolted 'to thellangc. This gear is enmeshed with the crown gear 49 and these gears will hereinafter be called timirngr gears. A blank holder (see Fig. 8) is bolted to gear 100, comprising in the present instance a plate 101 and ring 102. To gether they form a receptacle the shape of the blank, indicated in Vthis view by 103. The blank is nres'sed into the receptacle or `holder by a circular block 104 against which the end of the ram S0 bears when it is moved forward by the pressure cam 82.

r-l`he following brief explanation of bevel'.

gears will make what followsI more easily understood: The teeth of bevel gears are constructed on imaginary pitch cones in the same way that the teeth of spur gears are constructed on imaginary pitch cylinders. The pitch cones of a pair of bevel gears would, if mounted on shafts in placeiof the bevel gears, drive each other by irlctionalv Contactin the same velocity ratio as given by the bevel gears thcn'iselves. The angle. formed by the axis and one side of the pitch cone is called the pitch cone angle, and the sum of the two pitch cone angles equals the center angle. The center 'angle equals the angle formed by thc axes of the cones, meas; ured on the side on which the contact ne tween the concs takes place. The pitch dialnitcr is the diameter of the hase of tho cori and since the pitch of a bevel gear is measured on a circle ot' the Same diameter. pitch circle will -bc understood to mean a circle of the same diameter as the base of the cone. The pitch cone radius is the distanceA from the apex of the cone to the perimeter 'of its base. Treating` the. pitch circle as the perimeter of a plane, this imaginary plane will hereinafter be called the pitch eplane of the gear.

4rlhc lnost connnon Jform oi* here] gear is one in which the pitch cono angle is less than 00 degrees. The timing` gear 100 is ol' this type, while the timing tg'car 40 is oi" a rarer typenthc pitch cou an'gle being 00 degrees. llns typexof gear 1s called a crown `errar. and although the term pitch conc ang-le" is usedlfaid will he hereinafter used in rc'lcru ring to the angle formed by the axis and the pitch conc. thIl pitch 'conc o'f u crown Q'car is in fact a plane audcoimidcs with what has already been referred to as the I pitch plane. The pitch diameter and thc outside diameter ol' a crown geur arc the same, while in any other kind ol' bevel gear the outside diameter is larger than thc pitch (.liauletcr. A\lorco\'cr` the pitch of the tooth is the. sana' at thc cx! rcmitics oi thc addenda or at the bases as ou thc pitclrlnc. These characteristics being' similar to those which distinguish a rack lroln a .spur gear. a crown gear is also known as a circular rack.

Referring' again lo Fig. H the raul H0 is seen to have a socket 10? iu its end, receiving' an extension 100. The cud of this extension. is a circular plane and coincidesI with the imaginary puch-plano o1E gear l0; The outside of block lll-l is conical and coincides with the imaginary pitch cone oi' gear 100. 'l`hcrci'orc. the block 104 rolls upon the end of tbe extension 100 just as tho pitch-cone o1I gear 100 rolls upon thc pitch-plane of gear 40. The block `10l is secured to thc extension 100 by a halland-soclwt joint. "lho hall 107 is carried by a stem 10H which is drawn inward by a compression spring 100, 'lhe block 104 is constantly held in a position which will enable it to engagethe blank without guidance, by, a supportingl block ll() `which fills the `space between its conical back and the plane of the extension 1.00 and keeps the other side of the cone in contact with the' plane. This supporting' block is carried on the end of an arm lll which is arranged to slide in a guide 112 carried by the base 25. rThe arm has a lngr 113 lyingin an annular groove 111. in the extension 100, whereby it is moved in unison with the ram so as to enable the block 110 to maintain its position whatever the position of the rain may he.

4 and removing it from the shrouds.

'lhe timing' wheel 34 carries two rings, 120 and 121, which are called controlling cams, by which the'arms Hl and 66 respectively are operated. ',l`hcsc rings are illustrated diagrammatically in Figs. 14 and 15, and 4For thel purpose of simplifying the explana'- tion they are represented by arrows as moving' in opposite directions, which in a sense they do. since the arms operate on opposite sides ofthe timing' wheel. Then the machine is at rest the roller 81A lies in the recess 120A and when the incline orcam 120B engages the roller it lifts the arm 81 rather abruptly until the roller reaches the incline or cani 120C. and in doing this it causes the pressure cam H2 lo more the collar 83 for- Ward a certain distance. This ressure cam is diagrammatieally illustrate in Fig. 16 and it is there seen that the coacting surfaces comprise respectively abrupt inclines 82A and 83A, and shorter but less abrupt inclines82B and 83B. The incline 120B moves the arm suiiiciently to carry the incliney 2A past incline 83A and bring the inclines 2B and 83B into action. This moves the rain far enough' to bring the circular block into close proximity to the blank which has been inserted in the holder. The incline 120C then lifts the arm farther but more slowly and before the roller reaches the level portion of the ring the' arm will have moved far enough to bring the plane 82C under the plane 83C. The comparatively easy incline 120C and inclines 82B and 82C aord ample power to press the blank firmly into the holder. I f desired the plate 101 may have radial ribs 115 adapted to sink into the blank and prevent it turning in the holder.

The roller 66A normally lies in recess 121A, and toward the latter-part of the blank clamping operation the incline 121B engages this roller and 'lifts arm 66, operating the pressure cam 67 and moving shaft 60 toward the blank. F ig. 16 illustrates the pressure cam 67 as well as it does 83 and it is to be understood that by the time the Y roller has reached the top of incline 121B Ias the ,abrupt `inclines correspo'ndingtb 82A and 88A will have completed their Work and the smaller inclines, corresponding to 82B and 83B, will have started into, action. The line X-X indicates the relative timing of the operations. By the time the center of roller 81A reaches this line the roller 66Al will have nearly reached the topof incline 121B and through the operation of the ressure cam 67 the die roll Will. have en moved into close proximity to the blan i,

The long incline 121C now continues movingl the pressure cam 67, which completes its work and its planes 67 C move onto the planes 69C of collar 69 (see Fig; l). It is these planes, therefore, which x the position of ther die-roll at the end of theioperation. Shortly before the Vtiming Wheel completes its revolution the decline 121D1arrives under roller 66A and allowsI the arm 66 to, return to its normal position, the spV ingll then moving the shaft 60 back an Withdrawing the die-roll. Immediately after the die-roll is withdrawn the decline 120D arrives under roller 81A and allows the ac'rm 81 to resume its normal position, the roller resting in recess-120A. About the time the roller 81A starts down the decline 120D the lug -35 engages roller 36 and throws out Ithe clutch.

When the operator inserts a blank he 'may if he desires move the circular block 104 up to the blank With lever 86, and for the urpose of holding the block inthis position until the pressure cam 82 getsi'into action a paw 122, pivoted to the base 25, drops behind the lever (see Fig. 2). This facilitates uniformity in the treatment ofV blanks as it enables the operator to get the machine all ready so he can start it the instant the blank attains the desired temperature. The blank 'is heated to a higher than rolling temperature, and after it is in place in the holder the operator Watches its color change, having nearby if desired some object of the re uired color, and when the blank attains this color he throws in the clutch. By this method a high degree of uniformity is attained in the product, since from the time the clutch is thrownl in cach blank automaticallyV receives exactly the same treatment. When' the blank is finished the pawl 122 prevents the spring 85 withdrawing the block 104 until the operator is ready to receive the blank. If the blank sticks in the holder it is forced out with a bar 123 which slides through shaft 92. This bar is operated with a lever 124.

The timing gear 49 and die-roll 64 are universal in`that they may be used to roll any bevel gear of the radius and pitch of the latter, from a pinion having the fewest number of teeth possible Without its becoming a crown gear. It is necessary, however,

to provide a timing gear having the same number of teeth that.the blank is to have. The die-roll is universal also in that it is capable of rolling standard teeth; i. e., teeth whose addenda and dedenda are equal, or teeth with unequal/addenda and dedenda. Fig. 18 shows diagrammatically a pinion with long addenda meshed with a gear having short addenda. From what has been said it Will be understood that the teeth of the timing gear 49 are constructed on an imaginary pitch-plane, while those of the timing gear 100 are'constructed on an imaginary pitch-cone, and that the teeth of these gears are so formed as to cause the cone to roll on the plane just as though they were real and rolling together withoutslipping. The blank becomes in effcctra continuation of the gear 100 whose pitch-cone is also the pitch-cone of the blank. That is, an ima inary cone within the blank rolls upon t e pitch-plane of gear 49 as though they were real and rolling together Without slipping. This being the case it is evident that the portion of a blank tooth outside of this cone is addendum and the portion inside of the cone .dedendum, and it is equally evident that the relative length of the addendum and dede'ndum depends upon the osition of the 125 will be standard; ifmore than half crosses' o the blank will have teeth with short addenda; if less the blank teeth will have long addenda. This can be 'regulated by serewinf the thrust bearing 72 one wa or the ot ier on shaft (50. Tile position of t e thrust bearing on the shaft may also be varied to compensate for wearing of the die and to permit dies of various thicknessesto be used. No change is necessary in the timing gears to effect this variation in the kind of teeth -formed on the blank.

Shrouds confining the toothed portion of the blank force the metal into the spaces between the die-roll teeth and help toinsure perfect teeth on the blank. The preferred type of shroud is shown in- Fig. 8 and has beendescribed.' A somewhat similar type is shown in Fig.'9. In both of these only the active part of the die-roll is between the sl'irouds, which affords opportunity for removal of any forgin scale which may have lodged on the die. n Fig.`10 the end of the plunger is enlarged andbears directly uponl the blank, at the same time shrouding the piortion of the blank which is being acted upon. In `Fig. 11 the inner part of the die is shruded and the outer part of the blank.A I n Fig. 12 the inner part of the blank is shrouded by a detachable circular block 130 against which an extension 131 carried by the plunger 8O bears. The end of the extension is a plane which coincides with the pitchplane and the block is conical. The blanksI shown in Figs. 9 and 12 are rings and are removed from the holder by pins 132 carried by a disk 133. If desired the disk may be ,mgmtheiltqthe bar 123 by a screw as in Fig.

i). In Fig.v 13 the die-roll is shrouded.

In Fig. 7 a manual blank clamping device is shown. The blank is inserted in a holder 135 carried on the end of shaft 9 2. An ar bor 131i formed on the end of a rod 137 which slides` in theshaft passes through the blank and enters a plate 138 mounted to rotate l011 an arni linka ball thrust bearing 140 being interposed. The arm 13!) carried by a sliding plate 141 which is mounted in guides 142 carried by the plate 90. The plate is connected by a right and left hand screw coupling 143 toa link 1H; theI other end of the `lilik is attached toa link 145, this link in turn being pivoted at 146 to the plate 90.

Links lll and l-l-i form a toggle which is operated by a level' 147 rigidly Secured to link l-I-. 'lhe rod 137 is connected at 148 to plate 1)() by a toggle composed of links 14S) and 150, and the knuckhl ol this toggle' is connected by a link ll to link 145 so it will be operated in unison with the toggle 144-1-15. When lever |17 is operated the .plattl 13H :and arbor 136 are moved in opposite dirmftions yand,obviously, the toggles give very great power with whiehto clamp a blank.

InfFig. 17 the timing gca'r49 and die-roll 64 are rigidly mounted on a shaft which is journaled in a bearing 160 carried by a plate 161. This plate is pivoted tothe base of the machine not seen) at 162, the axis of the pivot passing through the pitch-plane of gear 49 at the periphery of said gear. The blank is carried by a suitable holder on a shaft journaled in a bearin 163 which iS pivoted to the base of the madliine (not seen) at 1G11 and is driven by a belt on pulley 165 at the otherend 0f the shaft. '.l`het1ming gear 100 is fixed to the shaft and is emncshed with gear 19 by swinging the bearing 16S-l on 1ts Divot, after which the bearing is secured to the base by bolts 166. The plate 161 iS moved by a hand wheel 167 'and is stopped by a set screw 16S when the pil li-plane of the die-roll and gear 49 reaches a point in line with the axis of pivot 161.

Another manually operated machine is illustrated in Figs. 1.) and 2l), where the timing gear 7S) is rigidly secured to a sleeve 475 mounted to rotate in a longitudinally fixed bearing 176, said bearing in turn being arranged to bolt to a base (not ishown). The die-roll (il is mounted on a shaft 177 arranged to move longitudinally in sleeve 175 and (-,ompelled to rotate in unison with the sleeve by a spline 178. Longitudinal. motion is imparted to shaft 177 by means of a hand operated screw 171). The timing gear 7E) meshes with the timing;r gea-r 10U, which is mounted on a shaft 18() arranged to rotate in a bearing 1Hl. The gear 100 is provided with a ret-ess to receive the blank, which is held therein by a plate 182 and bolt 18?), a portion only of which ls shown. Shaft ll) is driven by means not shown and it is evident that the gears 7!) and 101) maintain synchronous relations betweth the teeth on tlnl die-roll and the teeth it is forming on the blank.`

Although I have disclosednumerous variations from the |n'eferrad embodiment of my invention it is not to be inferred thatritsapplication-is limited to said embodiment and variations. It is limited only by the scope of the appended claims.

Having described my invention in such terms as to enable any one Iskilled in the art to which it appertains to make and use it, I claim: y

1. In a machine for rollingl gears, a toothed die-roll whosei pitch diameter and outside diameter are equal, means' for mountinga blank with a portion of its working face contiguous to the working face Of'the blank, meansfor imparting relative motion between the die-roll and blank whereby other portions of their workingl' aces are brought successively into similar contignity, and means foi-'moving tbc die roll longitudinally and causing its teeth to sink into and form teeth on the blank.

2. In a machine for 'rolling gears, a

rite

tteeth thereon, an

toothed die-roll whose pitch diameter and outside diameter are equal, mea ns for mounting a blank with a portion of its working face contiguous to the working face of the die-roll, means for rotating the die-roll and blank, and means for moving thc rotating die-roll longitudinally and causing its teeth to sink into and form teeth on the blank.

3. In aV g'ear rolling machine, a toothed die-roll whose pitch diameter and outside diameter are equal, means for supporting a blank, means for rotating the die-roll and blank, means for lmoving the die-roll longitudinally and pressing its teeth into the blank to form teeth thereon, and means for maintaining synchronous relations between the die-roll teeth and the teeth they are forming on the blank.

4. In a gear rolling machine, means for supporting a blank, i toothed die-roll whose pitch-line and addendum-line are equal, means for rotating the die-roll and blank, and means for moving the die-roll longitudinally and ressing it against the blank to form teeth t ereon. v

5. In a gear rolling machine, means forV sup orting a blank, a toothedndie-roll whose ptc -llne and addendum-line are equal, means for rotatin the die-roll and blank, means for moving t e die-roll longitudinally andfpressing it against the blank to form means Vfor maintainn synch; :nous relations between the die-ro teeth the teeth. on the blank.

6. In-a gear rolling machine, means for sup o rting a blank a toothed die-roll whose Illl-.line and addendum-line are equal, means for moving the die-roll longitudinally and pressing it against the blank and means for imparting relative movement between the die-roll and blankAi whereby the die-roll is caused t roll on thetace of the blank. I

7. In a' gear `rolling machine, means for sup rting a blank, a toothed die-roll whose pitch-line and addendum line are equal, means for moving the die-roll lon 'tudinally ,and pressing it `against the la-nk,v

means for imparting` relative movement between the die-roll and blank whereb' the die-roll is rolled on the face of the lilanlry and teeth formed thereon, maintaining synchronous relations between the die-roll teeth and the blank.

8. In a gear rolling machine, means for sup orting a blank, a toothed die-roll whose pitc -line and addendum-line are equal means for rotating the die-roll and blank an means for reducing movement of approach between tige die-roll and blank, Said a proach being inA a direction parallel to t e die-roll axis. v 9. In a gcar rolling machine, means for supporting a blank, a die roll, means yfor and means for those it is forming on Y 'roll and pressing it 'against the causing the die-roll to roll teeth on the blank, and automatic means cooperatively associated with the last mentioned means, for terminating the rolling operation when it has continued for a given length of time.

10. In a gear rolling machine, a die-roll, means foi-'causing it to have rolling engagement with a blank and roll teeth thereon, and means cooperatively associated with the aforesaid means for causing the die-roll to continue said rolling engagement for a limited time after the teeth have been formed, without materially changing the' formof the teeth. Y

11. In a gear rolling machine, a die-roll, meant'I for causing it and a blank to simul taneously have rolling engagement `with and approach each other for a limited time, and means cooperatively associated with the aforesaid means for suspending the movement of approach and continuing the rollin engagement alone for a limited time.

12. In a gear"^rolling machine, a die-roll, means forsupporting a blank, means -for producing relative movement of approach therebetween whereby to press the vdie-roll and blank together, means independent of their contact for causing the die-roll to roll on the blank, and means for causing said relative movement of approach to occur at any predetermined velocity relative to th velocity of said rolling motion between the die-roll and4 blank.

13. In a gear rolling machine, a die-roll, means for supporting a blank, means for producing relative movement of approach therebetween whereby to press the die-roll and blank together, means independent of their contact or causing the die-rol1 to'- roll on the blank, and'automatic means for relievingl the ressure between the die-rollend blank after' the teeth. of the formerhave sunk to a. predetermined depth in the blank.

14.- In agear rolling machine, a die-roll, means for supporting a blank, meanswfo'r producing relative movement. of ap roach therebetween whereby to press the` ie-roll and blank together, said means completing the movement of approach 1n a predeter-.

mined time, means independent of their 'contact for causing the die-roll to roll on the blank] the die-roll and the blank.

` 15. In a gear rolling machine, a dieron, means for supporting a blank, means independent of the contact for rotating the dieroll and blank, means for movin V the dieb ank, and automatic means for withdrawing the dierollafter its teeth have penetrated the blank to a predetermined depth and it has remained enmeshedto said depth and rotated therewith for a 'predetermined length of time.

and automatic means for separating lio 16. In a gear rollin" machine, a circular toothed die, a blan (-holder, means for clamping a blank therein, means for rolling the die on the blank, means for producing movement of approach, whereby to press the die teeth into the blank ,-oncnrrently with said rolling operation, n'hereby to form teeth on the blank, means for separating the die and blank after the teethare formed,

and means for f introlling and timing thev several operations, whereby (o) the operation of clamping the blank is pertornicd during a period of time equal to that which would be required for the die to traverse the blank a given number of times; (b) the die teeth are made to penetrate the blank to a predetermined depth while the die traverses the blank a given number of times; (c) the die is made to traverse the blank a given number of times with its teeth emneshed to said depth, and (fl) the die and blank are separated.

17.Y In a gear rolling machine, a die-roll, a blank holder, means for rotating them, a controlling and timing element, and means controlled by said element for successively (a) clamping a blank in the holder, (b) bringing the die into engagement with and causing its teeth to sink to a predetermined depth in the blank, (o) causing the die and blank to rotate for a time with their teeth enmeshed'to said predetermined depth, ((7).

separating the die and blank, (e) releasing the blank so it may be removed trom the holder, and (f) sto ping rotation ol the blank holder; each o said operations, n to f inclusive, being performed while the.blank rotates a given number of revolutions.

18. In a gear rolling machine, a toothed die, means for supporting and rotating a blank, means for pressing the die .teeth into the rotating blank, thereby forming teeth on the blank, means for separating the die and Hank, and means t'or controlliiao` and timing said operations, whereby the die teeth are. made to )enctrate the blank to n predetermined depth while the blank rotates a given number of revolutions. where they are allowed to remain while thc blank rotatcs a given nlnnbcr ot! revolutions. at'tcr which the die is witlulrawn.

li). Vln a. gear rolling machine. a Itoothed die, a rotatable blank-ladder. means` l'or clamping r blank in thc holder, means for pressing the die tccth into a blank clamped in the rotatingr holder, \\-'hcrcby to t'orm teeth ou the blank. aml means' foucontrol|ing and timing said operations. whereby each is made to occur while the blank rotates a given number ot revolutions.

2t). In a gear rolling machine, means l'or supporting.;` a blank, a flie-roll, means for mtating` both, amlmca'nsI for pressing the die roll and blank together, the pressure bein;r

substantially parall'izl to the axis of the dieroll.

21. In a gear rollin machine, means for supporting a'blank, a die-roll, means for rotating both, means for pressing the die-roll and blank together, the pressure beingr substantially parallel to the axis of the die-roll, and a bearing behind the portion ot' the dieroll which is in contact with the blank.

22. In a gear rolling machine. a die-roll, means for supporting a blank. means t'or rotating the die-roll aml blank supportingl means at an invariable velocity ratio, means for producing relative movement ot' approach therebetwtam whcreb \"`,ihe dic-roll and blauk,are pressed together and teeth t'ormcd on the blank. and shrouds arranged concentric to the blank for the purpose of coniiuiug portions of the displaced metal of the blank' not dirci-thY acted upon b v the die-roll.

23. ln a gear rolling machine. a tliei'oll. means for supporting a blank, means t'or rotating the ilicaoll and blank supporting means at a lixed velocity ratio, means for producing relative movement ot' approach therebctwm-u \\'bcreb v the dic-roll and blank are pressed together. and shrouds arranged concentric to the blank to prevent. displacement ot' metal save toward the dieroll.

2t. ln a lg'ear rolling machine. a die-roll, meansl for supporting a blank, means for rotating the dic-roll aml blank. means t'or producing rclatvc movement of approach thcrcl-wtwian whereby the dic-roll and blank arc prcssctI togcthcr. a shroud arranged concentric to thc blank to prevent lateral displacement oll metal. and means For maintaining unil'orm velocity ratio between the dc-roll and shroud.

35. ln a bcvcl gear rolling machine. a dieroll adapted to l'orm tbc,tccth ot' bevel gears, means For supporting a bevel gear blank, means l'or rotating thc die-roll and blank, meansl l'or producing relative movement tllcl'clictwccn \\'licrcli v to l'orui bevel gear teeth on the blank. and shrouds to confine thc blank and prevent displacement ot' metal save toward thc dic-ro||.

2li. ln a machine for rolling bcvcl gears, a dic-rol| adapted lo roll teeth on a bevel gear. means l'or supporting a bcvcl gear blank. means for rotating` tbc dic-roll and blank` means l'or producing rclativc movement therebetween whereby the blank and dic-roll are pressed together. and shrouds between which thc dic-roll teeth are located whilc they acl upon thc blank. said sbrouds being so arranged as not to conlinc the in- :utivc teeth olI thc dic-roll. so that particles ol' scale or other silbstauccs can bc thrown oll' by ccutril'ugal l'orce.

27. ln a gear rolling machine. a dica'oll,

.circular block adapted to means for supporting a blank, means for producing relative movement of ap roach therebetween whereby to press the ie-roll and blank together, means for imparting relative movement therebetween whereby t0 cause the die-roll to roll on a blank carried by the blank supporting means, said means being independent of contact between the die-roll and blank, and a shroud arranged concentric to the blank to prevent lateral displacement of metal.

28. In '-a machine for 'rolling bevel gears,

outer tooth-receiving (part of the blank, a`

circular block adapte to press the blank into the holder, said block having a rim to shroud the inner tooth-receiving portion of the blank, a die-roll, means forcausing the die-roll to enter the space between said shrouds and roll teeth on, the blank, and a plunger movable. parallel to the'axls of the die-roll wherebythe circular block is pressed against the blank.

30. In a machine for rolling bevel gears, a rotatable blank holder having a rim to shroud the outer tooth-receiving portion of the blank, a circular block adapted to press the blank into the holder, said lock having a rim to shroud the inner tooth-receiving part of the blank, a die-roll, means for causing the dic-roll to enter the space between the shrouds and roll teeth on the blank, and a ball-and-socket centling device for the circular block.

31. In a machine for rolling bevel gears, a blank holder having a rimrto shroud the outer tooth-'recei ving portion of the blank, a circular block adapted to press the blank into the holder, said block having a rim to Shroud the inner tooth-receiving part of the blank, a die-roll, means for causing the dieroll to enter the s ace between the shrouds and roll teeth on t e blank, a plunger movable parallell to the axis of the die-roll whereby the circular block is pressed against the blank, and a ball-and-socket connection between the plunger and block.

32. In a machine for rolling bevel gears, a blank holder having a Lrim to shroud .the outer tooth-receiving portio of the blank, a ress the blank into the holder, said block aving a rim to shroud the inner tooth-receiving part of the blank, a die-roll, means for causing the die-roll to enter theV vspace between the along a line angular to the axis of the blankshrouds and troll teeth on the blank, and a 65 plunger movable parallel to the axis of the die-roll to press the block against the blank, said plunger having rolling contact with the block.

33. In a machinelifor' rolling bevel gears, means for supporting a blank, comprising a blank holder and a circular block, the former to receive andthe lattereto keep the blank in the former, each havin a rim to shroud the tooth-receiving part o the blank, means for pressing the block against the blank, a die-roll, and means for causing the dieroll to roll teeth upon the shrouded portion of the blank. 4

34. In a machine for rolling bevel gears, means for supporting a blank, comprising a blank holder and a circular block, the former to receive and the latter to vkeep the blank'in the former, each havin arlm to shroud the tooth-receiving part o the blank, a plunger movable along a line angular to the axis of the blank-holder and block, to' press the block against the blank; a die-roll and means for causing it to roll teeth on4 the blank.

35. `In a machine for rolling bevel gears,y means for supporting a blank, comprising a blank-holder and a circularblock, the former to receive and the latter to keep the l blank in the former,.each havin a rim` to shroud the tooth-receiving part o the blank,

a plunger movable along a line an lar to the axis of the blank-holder and lockto press the block against the blank, said plunger having rolling enga ement With the lock'; a die-roll and means or causing it'to roll teeth on the blank.

36. In a machine for rolling bevel gears, means for supporting a blank, comprisin a blankholder and a circular block, the ormer to receive and the latter to kee the blank in the former, each havin a rim to shroud theA tooth-receiving part o the blank, a plunger movable along a line angular to the axis of the blank-holder and block vto press the block against the blank, said block being attached to the plunger by a ball-andsocket device; a die-roll and means for callsing it to roll teeth on the blank. l

37. In a machine for rollin 'Bevel nge f, ,115 means for supporting a blan com'ri` ."1 a blank-holder and 'a circular bloc L, former to receive and the latter to keepi't 4e i blank in `the former, a plunger movable holder and block to press the block against thc' blank, said plunger having rolling engagement with the block; 'a die-roll and means for causing it to roll teeth on the blank. v

38. In a machinel for rolling bevel gears, means for supporting a blank, comprislng a blank-holder anda circular block, the former to receive and the latter to keep the blank in the former, a plunger movable along a line angular to the axis of the blank-holder and block to press the, block against the blank, the block bein attached to the plunger by a ball-and-soc et device, and means for maintaining the block in approximately7 the required position With reference to the plunger when it is not in contact with a blank; a die-roll and means for causing it to roll teeth on the blank.

39. In a machine for rolling bevel gears, means for supporting a blank, comprising a blank-holder and a clrcular block, the former to receive and the latter to keep a blank in the former, a plunger movable along a line angular to the axis of the blank-holder and t0 press the block against the blank, the block being attached to the plunger by a ball-and-socket device, and a supporting member mounted to move with the plunger and keep theblock in approximately its correct angular position; a die-roll and means for causing it to roll teeth on the blank. 40. In a machine for rolling bevel gears,

. means for supporting a blank, comprising a blank-holder and a circular block, the former to receive and the latter to keep a blank in the former, a plunger movable along a line angular to the axis of the blank-h`oldcr and block to press the block against the blank, the end of the plunger and the block being so formed that they may have rolling engagement with each other, a ball-aml-soelnft device for attaching the block to the plun` ger, and a supporting member arranged to maintain the block in approximately its correct position with reference to thc plunger when the block is not in contact with the blank; a die-roll and means for causing it to roll teeth on the blank.

41. In a machine for rolling bevel gears, a blank holder, a diea'oll, a member adapted to press a blank into the holder for the purpose of holding it firmlyr therein While teeth are being rolled on it. said member having a surface of the same form as the pitch-surface of the die-roll, and means for forcing said member toward the blank until said surface coincides with the pitch surface of the die-roll.

42. In a machine for rolling bevel gears, a blank holder, a die-roll, a member adapted to press a blank into the holder for the purpose of holding it firmly therein While teeth are being rolled on it, said member having a surface of the same form as the pitch-sun face of the die-roll, a circular block interposed between said member and the blank, and means for forcing said member against the circular block and pressing said block toward the blank until the surface 40i" Said member coincides with the pitch-surface of the die-roll, the contacting surface of the block having the same form as the pitch surface of the blank thus adapting the block and member to roll together su stantially as `the pitch-surfaces of the die-roll and blank roll together.

43. In a gear rolling machine, means for supporting a blank, a toothed die roll, means for rotating both at equal pitch-line velocity, and means for producing relative movement of approach, said means being adapted to continue the movement of approach until the pitch-line of the die and that of the blank have attained any desired relative position, even until they overlap.

44. In a gear rolling machine, means for supporting a blank, a toothed die roll having tapered converging teeth and adapted to roll teeth on a bevel gear, means for r0- tating the die roll and blank at equal pitch line velocity, and means for producing relative movement of approach, said means being adapted to continue'the movement of approach until the pitchflines have attained any desired relative position, even until they overlap.

45. In a gear rolling machine, means for supporting a blank, shrouds to confine the tooth-receiving part of the blank, a die-roll,

means for moving the die-roll longitudinally to engage and press its teeth into the blank, and means for rotating the die-roll and blank.

46. In a gear rolling machine, means for supporting a blank, shrouds to confine the tooth-receiving part of the blank, a die-roll, means tor moving the die-roll longitudinally to engage and press its teeth into the blank, means for rotating the die-roll and blank, and means for maintaining fixed velocity ratio between the dieroll and blank.

47. In a gea r rolling machine, means for supporting a blank, shrouds to confine the tootlrreceiving part of the blank, a die-roll, means for moving the die-roll longitudinail)Y to engage and press its teeth into the blankmeans for rotating the die-roll and blank, and means for maintaining synchronous relations betvveedthe die-roll teeth and the teeth it is forming on the blank.

48. In a machine for rolling bevel gears, a blank holder having a rim to shroud the outer circumference of the tooth receiving portion of a blank, a plunger movable with reference to the blank holder, and a circular block carried by the plunger and adapted to be pressed against the blank to hold it in the blank holder while teeth are being rolled upon the blank.

49. In a machine for rolling bevel gears, a blank holder having a rim to shroud the be pressed against the blank to hold it in the blank holder while teeth are being rolled upon the blank, said block being adapted to support the inner circumference of the portion of the blank which is being acted upon by the die-roll.

50. In a gear rolling machine, a crown die-roll, means for supporting a blank, and means for moving the die-roll longitudinally and causing it to roll teeth on the blank.

5l.l In a gear rolling machine, a crown die-roll, means for supporting a blank, means for rotating the die roll, and means for moving the rotating die-roll longitudinally and pressing it against the blank.

52. In a gear rolling machine, a crown die-roll, means for supporting a blank, means forrotating the die-roll and blank, and means for moving the die-roll longitudinally and pressing 1t against the rotating blank.

53. In a gear rolling machine, a crown die-roll, means for supporting a blank, (giears whereby the dieroll and blank are ma e to rotate at equal pitch-line velocity and means for moving the die-roll longitudinally and pressing ,it against the blank.

54. In a gear rolling machine, a crown die-roll, means for su porting a blank, means for moving the die-roll longitudinally and causing it to roll teeth on the blank, and means for maintaining synchronous relati ns between the teeth on the die-roll and those which are bein formed on the blank.

55. In a gear rolling machine a crown die-roll, means for supporting a blank, means for moving the die-roll longitudinally and pressing it against the blank, and means for rotating the die-roll and blank, said means maintaining synchronous relations between the die-roll teeth and those which are being formed on the blank.

56. In a gear rolling machine, a pair of gears rotatably mounted with their teeth enmeshed, a blank-holder mounted to rotate in unison with one of said gears, a crown die-roll mounted to rotate upon the same axis as and in unison with the other gear, and means for moving the die-roll lon tudinally toward a blank mounted in t e blank-holder.

57. In a gear rolling machine, a pair of .gears rotatably mounted with their teeth enmeshed, a blank-holder mounted to rotate in unison with one of said gears, a crown die-roll mounted to rotate upon the same axis as and in unison with the other gear, and means for moving the die-roll longitudinally with reference to said gearand pressing it against a blank in the blankholder.

58. In a machine for rolling bevelgears, a* pair of gears rotatably mounted with their teeth enmeshed, a blank-holder mounted to rotate in unison with one of said gears, a dieroll mounted to rotate in unison with the other gear, means for producing relative .movement of approach whereby the die-roll -aud blank are brought into contact and teeth formed on the blank, and means for insuring that said movement of approach shall be per endicular to the pitch-cone radii.

59. An a machine for rolling bevel gears, a blank-holder, a rotatabl mounted die-roll, and a pivotal connection between the blankholder and die-roll mounting, the axis of said pivot being perpendicular to the axis of the blank and crossing it at the apex of the pitch cone of the blank.

60. In a machine for rolling bevel gears, a blank-holder, Aa rotatably mounted die-roll, a pivotal connection between the blankholder and die-roll mounting, said pivot being so positioned that its axis passes perpendicular to the axis of the blank through the apex of the pitch-cone of the blank, and means for fixing the relative positions of the blank holder and die-roll mounting so the blank and die-roll axes will form any desired angle. u,

61. In a machine for rolling bevel gears, a blank-holder, a rotatably mounted die-roll, a pivotal connection between the blank-holder and die-roll mounting, said pivot being so positioned that its axis passes perpendicular to the axis of the blank through the apex of the pitch-cone of the blank, and a graduated scale and index whereby to determine the angularity of the die-roll and blank axes.

62. In a machine for rolling bevel gears a base, a die-roll journaled thereon an arranged to move longitudinally with reference to the base, and a blank-holder journaled in a swiveled bearing with its axis in the same plane as that of the die-roll, the swivel axis passing perpendicularly through the blank-holder and die-roll axes.

63. In a machine for rolling bevel gears, a base, a die-roll journaled thereon, and a blank-holder journaled in a swiveled bearing with its axis in the same plane as that of the die-roll, the swivel axis passing perpendicularly through the blank-holder axis.

64. In a machine for rolling bevel ars, a base, a die roll journaled thereon, a b ankholder journalcd in a swiveled bearing with its axis in the same plane as that of the die- .crosses the axis ofthe blank.

65. In a 'machine Afor rolling bevel gears,

a base, a rotatable die-roll mounted thereon, a blank-holder journaled in a swivelcd bearing with its axis in the same plane as that of the die-roll, the swivel axis passing perpendicular-ly through the axis ot the blankholdcr, means for rotating the die-roll and blanksholder. and means for moving the ro- 1tating die-roll toward the blank whereby to cause it to form teeth thereon.

G6. In a machine for rolling bevel gears, a base, a rotatable die-roll moui'ited thereon, a rotatable blank-holder journaled in a swiveled bearing with its axis in the same plane as that of the dic-roll, the swivel axis passing perpendieularly through the axis of the blank-holder and said plane; means for moving the die-roll into contact with and causing it to form teeth on a blank in the holder, and means for fixing the swiveled bearing in any desired position.

67. In a machine for rolling bevel gears, a base, a rotatable die-roll and a rotatable blank-holder mounted tliereon, a swivel dcviee whereby the angle formed by the die? roll and blank-holder axes may be varied, the axis of the swivel passing perpendicularly through said axes at the point where the)7 cross when rolling of the blank is com- .pleted, and means for fixing the angularity of said axes at a required degree.

68. In a machine for rolling bevel gears. a base, a timing gear mounted to rotate there on, a die-roll mounted to rotate upon the same axis and in unison with the timing gear, a blank-holder mounted in a. swiveled bearing, a timing gear removably mounted to rotate upon thr` same axis and in unison with the blank holder, the axis of the swivel passing perpendicularly through the axis of the blank-lxolder` and being so located that by swinging the blank-holder thereon its timing gear will he brought into working relationship with the die-roll timing gear` and means for fixing the swiveled bearing in a required position.

G9. In a machine for rolling bevel gears. a base. a pair ot journals carried therehv. one of which is arranged to swing upon a swivel Whose axis passes perpendicularlv through its axis, one of said journals carrying a die-roll and the other a blank-holder, means for fixing the swiveled journal in a. desired position with reference to the other journal, and means for causing the die-roll to form teeth upon a blank in the blankholder.

70. In a machine for rolling bevel gears, a base, a pair of journals carried thereby, one of which is arranged to swing upon a swivel whose axis passes perpendicularly through its axis. one of said journals carrying a dieroll and the other a blank-holder, a timing gear mounted upon each journal, means for fixing the swiveled journal in a position where its timing gear meshes with the other gear, and means for causing the die-roll to engage and form teeth on a blank in the dieholder.

`71. ln a machine for rolling bevel gears, a base, a pair of journals carried thereby, one of them being arranged to swing on a swivel, the axis of which passes perpendicularly through the journal axes at the point where hev cross, and means for fixing the swiveled journal in a desired position with reference to the other journal; a die-roll carried by one journal. a blank-holder carried by the other, and means t'or moving the die-roll longitndinallj1 and causing it to roll teeth on a blank in the holder( 72. In a machine for rolling bevel gears, a hase, a pair of journals carried thereby, one ot' them being arranged to swing on a swivel, the axis of which passes perpelxdicularlj7 through the 'iournal axes at the point where they cross,y a timing gear mounted upon each journal, and n ans for Iixing the swiveled journal in such position that said gears are properly cmneshed; a die-roll carried by one journal, a blank-holder carried by the other` and means for moving the die-roll longitudinally and causing it to roll teeth on a blank in the holder.

7B. ln a machine for rolling bevel gears, a base, a timing gear journaled thereon; a dicroll mounted concentric to and arranged to rotate in unison with said gear, but movable hm, itudinall)v with reference thereto; a second timing gear and a blank-holder united and mounted to rotate in a swivclcd bearing on said base with the gears enmcshed. the axis of said swivel passing perpendicularly through the gear axes at the point where they cross; means for fixing the swivclcd bearing at a point where the gears are properlj7 emneshed, means for rotating the gears. and means` for moving the die-roll longitudinally and pressing it against a blank in the holder'.

T4. ln a machine for rolling bevel gears7 a basi-` a crown gear journalcd thereon, a crown die-roll mounted concentric to and arranged to rotate in unison with said gear, but movable longitudinally with reference thereto; a bevel galr and a blank-holder united and mounted to rotate in a swiveled bea ring on thc base. with the gears enmeshed the axis of the swivel passing perpendicularl)r through the axes of the gears at the point where they cross, which point is also coincident to the pitch plane of said crown gear; means tor fixing the swiveled bearing at a point where the gears are properl)T enmeshefh means` for rotating the gears. and means for moving the die-roll longitudinalby and pressing it against a blank in the blank` holder.

7 5. In a machine for rolling bevel gears, a 

